Eighteen-year-old Briana Chavez was just about to try on a sports bra last Friday when she noticed something very suspicious on the floor of her dressing room.

"Right when I bent down to put my phone in my shoe to start changing, that's when I see this shiny thing in the corner of my dressing room."

Briana never noticed the suspect in the store, but surveillance cameras show him appearing to browse for about an hour before the serial Peeping Tom is suspected of striking again.

The manager at Plato's Closet called police and Briana started her own investigation. A store employee knew the suspect was named David Chavez and Briana tracked him down and began sending him messages on Instagram-- about 10 minutes later she got a response.

"He immediately said, 'I deleted everything, I have nothing,' and that's when I was like, okay he just admitted it."

But Briana pressed on, asking him, "Why would you do this" then she told him, "You're sick."

"That's when he was saying this was just a lapse of judgment. Don't let this be who I am because it's not, it was an accident. And that's when he had said that he was trying to take a picture of himself in the dressing room and his phone fell."

Briana did not buy it and now investigators are wondering if Chavez has even more victims, because store employees said he is a familiar face.

"We're trying to backtrack and see how many times he was there. What he was doing there-- but the store owner says he is there frequently," said Sgt. Daniel Macias, Fresno Police Department.

Tuesday morning, sex assault detectives woke up Chavez with a search warrant for evidence-- they took electronic devices to forensically analyze.

"He was cooperative. He didn't want to talk to us but he did cooperate with the service of the search warrant," said Macias.

Just last month Chavez pleaded no contest to two misdemeanor counts related to secretly recording people in a bathroom. A search warrant revealed the recordings were at the Quik Stop Convenience Store in Caruthers.

Chavez is set to return to court next month and is supposed to bring proof he has a phone that does not have any recording device. By then officers are planning to have another charge filed in the latest case.